<form class="mb-20" method="get" action="{:\\think\\Url::build($Request.action)}">
    栏目
	<select class="cat_id" name="cat_id">
			{volist name="cat" id="vo"}
				<option value="{$vo.id}">{$vo.cat_name}</option>
			{/volist}
	 </select>
    <button type="submit" class="btn btn-success" id="" name=""><i class="Hui-iconfont">&#xe665;</i> 搜索</button>
</form>